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Scientists watch a memory form in the brain of a living fish

quantamagazine.org

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Re: Scientists watch a memory form in the brain of a living fish

#11

Post by randomsilence »

rakkhi wrote: post #5

In fish... "Contrary to expectation, the synaptic strengths in the pallium remained about the same regardless of whether the fish learned anything. Instead, in the fish that learned, the synapses were pruned from some areas of the pallium — producing an effect “like cutting a bonsai tree,” Fraser said — and replanted in others." This is a very counter intuitive. So there are existing neural connections (formed someho…

That's consistent with the way, children react to languages and faces. When we are born, we are open to all languages. When we grow up, we only remain receptive to the language structures to which we had been exposed previously. Of course it's always possible to learn a new language, but it is easier with previous exposure.

(citation needed)

Re: Scientists watch a memory form in the brain of a living fish

#12

Post by randomsilence »

>While a developing mammalian brain grows by just getting bigger — “inflating like it’s a balloon” — the zebra fish brain almost turns itself inside out “like a popcorn kernel, so those deep centers are up near the surface where we can image them.

Makes me wonder: How big is the hidden cost of destroying rain forests and other habitats? Every species that we lose is the loss of genetically encoded knowledge that could be very useful at some point.

Could we protect the environment by making investment fonds eligible to the profits from genetic knowledge on the territory they own?

Re: Scientists watch a memory form in the brain of a living fish

#13

Post by DeWilde »

twoxproblematic wrote: post #4
gleenn wrote: post #2

Super cool, they added fluorescent proteins that activate when the neurons fire and did it in a Zebrafish which is transparent so they could literally watch the memories forming. Interesting also they wanted to keep the light as low as possible to not scorch the little guys.

Are they not like rats where they "sacrifice" them regardless of the testing done?

Inflicting unnecessary pain during testing would be counter-productive to the testing goal.

Re: Scientists watch a memory form in the brain of a living fish

#15

Post by sva_ »

randomsilence wrote: post #12

>While a developing mammalian brain grows by just getting bigger — “inflating like it’s a balloon” — the zebra fish brain almost turns itself inside out “like a popcorn kernel, so those deep centers are up near the surface where we can image them. Makes me wonder: How big is the hidden cost of destroying rain forests and other habitats? Every species that we lose is the loss of genetically encoded knowledge that coul…

> How big is the hidden cost of destroying rain forests and other habitats?

Incalculable, since we have no idea what we're losing?

Re: Scientists watch a memory form in the brain of a living fish

#16

Post by sva_ »

rakkhi wrote: post #5

In fish... "Contrary to expectation, the synaptic strengths in the pallium remained about the same regardless of whether the fish learned anything. Instead, in the fish that learned, the synapses were pruned from some areas of the pallium — producing an effect “like cutting a bonsai tree,” Fraser said — and replanted in others." This is a very counter intuitive. So there are existing neural connections (formed someho…

I don't think it is counter intuitive (maybe if you hold a strong opinion, it is.) There's a growing body of evidence that brains, to some degree, learn by removing connections, and in some cases, add connections elsewhere.

I think part of learning is, that we have some general idea about something, but it turns out to be inaccurate, so we need to specialize it (and get rid off the old connection.) I'm speculating though.

I'm a bit confused by the "replanted in others" part though. I'd assume, overall, there is a net loss of synapses when learning (and hence learning becomes more difficult as we age - there just isn't enough entropy to prune away.)

See also https://www.tcd.ie/news_events/articles/why-do-we-forget-new...

And Discussion https://news.ycombinator.com/item?id=29940435

The article also has some older references - the idea isn't new.

Re: Scientists watch a memory form in the brain of a living fish

#17

Post by loveJesus »

rakkhi wrote: post #5

In fish... "Contrary to expectation, the synaptic strengths in the pallium remained about the same regardless of whether the fish learned anything. Instead, in the fish that learned, the synapses were pruned from some areas of the pallium — producing an effect “like cutting a bonsai tree,” Fraser said — and replanted in others." This is a very counter intuitive. So there are existing neural connections (formed someho…

No post body was provided.

Re: Scientists watch a memory form in the brain of a living fish

#19

Post by jonsen »

rakkhi wrote: post #5

In fish... "Contrary to expectation, the synaptic strengths in the pallium remained about the same regardless of whether the fish learned anything. Instead, in the fish that learned, the synapses were pruned from some areas of the pallium — producing an effect “like cutting a bonsai tree,” Fraser said — and replanted in others." This is a very counter intuitive. So there are existing neural connections (formed someho…

Subtractive sculpture:

https://artistryfound.com/what-is-subtractive-sculpture/

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